Fire sprinkler control system



Aug. 6, 1963 J- E. JOHNSON 3,100,017

FIRE SPRINKLER CONTROLBYSTEM Filed Sept. 27, 1962 3 Sheets-Sheet l DELAYINVENTOR. JOSEPH E. Jomvso/v ATTOENEYS 1963 J. E. JOHNSON 3,100,017

FIRE SPRINKLER CONTROL SYSTEM Filed Sept. 27, 1962 3 Sheets-Sheet 2INVENTOR. Jomvsmv WM MW JOSEPH E ATTORNEYS Aug. 6, 1963 J. E. JOHNSON3,100,017

FIRE SPRINKLER CONTROL SYSTEM Filed Sept. 27, 1962 5 Sheets-Sheet 3 TlME1 DELAY I INVENTOR. J S P P. Jamison! ATTORNEYS rates 3,109,917 FREE SPER CONTRQL SYSTEM This invention relates to fire extinguishing systemsand more particularly to improvements in apparatus for the automaticcontrol of fire extinguishing fluid flow through distributor pipes.

There are three :broad classes of fire extinguishing systems oftenreferred to respectively as the wet pipe system, the dry pipe system andthe empty pipe system. In the usual wet pipe systems water or awater-antifreeze mixture is carried in distributor pipes under supplyline pressure until one or more sprinkler heads on the pipes are opened,for example, by fusing. This causes a flow in the system for dischargethrough the head. An automatic valve opening is often accompanied by theflow for initiating an alarm.

In common dry pipe systems no water is carried in the distributor pipesuntil one or more of the sprinkler heads are opened, the flow paththrough a main valve into the distributor being sealed off by airpressure in the distributor system bearing against a pressure sensitiveclapper in the main valve. When a sprinkler head opens the air in thesystem escapes causing pressure to drop to a point where the clapperopens for flooding the distributor pipes with fire extinguishing fluid.

In empty .pipe fire extinguishing systems, the distributor pipes oftencontain nothing but air under normal atmospheric pressure and mayemploy, in contrast to the wet and dry pipe systems described above,unobstructed or open sprinkler heads. In some instances, empty pipesystems carry closed heads whereby a slight air pressure may bemaintained in the distributor pipes for supervision and/ or to restrictfluid discharge to the vicinity of a fire. Triggering is oftenaccomplished by lowering the pressure in a pilot line containing air orantifreeze solu tion under pressure and generally having temperatureresponsive valves associated therewith which operate in a similar mannerto the temperature sensitive devices included in the sprinkler heads onthe distribution pipes of the wet and dry pipe systems. The pilot linein many empty pipe systems contains gas and terminates in a plurality ofenlarged gas filled bulbs. Triggering is then initiated by a rise in gaspressure due to bulb heating.

Various additional fire extinguishing systems have been developed whichare essentially hybrids of the above described systems to overcomeparticular individual disadvantages thereof and many specialized controlmechanisms have heretofore been used with the respective systems toprovide certain refinements in operation. A serious problem or defectwhich has continued to exist with respect to all common types of fireextinguishing systems is that after triggering and operation manualshut-off is usually required and the manual shut-off completelydeactuates the automatic features of the system. Thus, if a smolderingfire breaks out after shut-01f, valuable time may be lost before manualactuation, permitting the fire to rage beyond control. Sometimes thereignited fire isolates the manual controls rendering the extinguishingsystem valueless to prevent total plant loss. Nevertheless, the Waterflow must be turned off as soon as practicable to avoid excess waterdamage and, where scarce, to save water. Automatic shut-off byspecialized apparatus responsive to temperature or flame radiation havebeen suggested mainly to avoid excess Water damage. Insurance andunderwriting agencies have generally disice approved same because theyare not sufficiently reliable, they tend to shut the sprinkler off afterthe fire is out but still smoldering, and, as with the common systems,they offer no provision prior to complex manual resetting forautomatically turning systems back on in case fire again breaks out.

The principal objects of the present invention are: to provide a highlyreliable sprinkler control system which is operative to automaticallyturn off fire extinguishing flow but is adapted to again initiate flowin case of a reignition; or provide such a control system which includestime delays which continue fluid flow for a predetermined period after asignal is received that the fire is out in order to better insureagainst reignition but yet hold Water damage to a practical minimum; toprovide such a control apparatus which operates electrically but willnot interfere with the usual mechanical operation of the sprinklersystem in case of electrical power failure before, during or after thefire; to provide an improved control apparatus which is easily adaptablefor use with Wet pipe, dry pipe, empty pipe or hybrid fire extinguishingsystems and which will not interfere with specialized devices refiningthe operation thereof; and to provide such a control system for fireextinguishing apparatus which is simple in construction and operation,low in cost and which should merit approval by even the mostconservative insurance and underwriting agencies.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings, wherein are set forth by way of illustration and examplecertain embodiments of this invention.

FIG. 1 is a fragmentary schematic partially crosssectional View ofcontrol apparatus embodying this invention and used on an empty pipesystem.

FIG. 2 is a fragmentary schematic partially crosssectional view ofcontrol apparatus embodying this invention and used on a wet or dry pipesystem.

FIG. 3 is a fragmentary schematic partially crosssectional main controlvalve shown in the open position and including a regulator forcontrolling output flow pressure.

FIG. 4 is a schematic wiring diagram illustrating the relationshipbetween electrical members in an embodiment of this invention.

Referring to the drawings in more detail:

The reference numeral 1 broadly indicates a fluid actuated main controlvalve which may be used for controlling fluid flow into a wet pipe, drypipe or empty pipe fire extinguishing distribution system. It is to beunderstood that, although the valve is shown in a single form,modifications in the relative sizes and configurations of the variousparts thereof may be desirable for adaptation to the specific systeminvolved. The valve 1 has a body 2 forming an inlet passageway 3 whichis connected to a source 4 of the fire extinguishing fluid, such aswater, under pressure. The body 2 also forms an outlet passageway 5connected to the fluid input 6 of a sprinkler pipe network indicated at7 in FIG. 1 (empty pipe system) and 8 in FIG. 2 (wet 'or dry pipesystem). The valve -1 includes a flow controlling disklike clapper 9operatively located between the inlet passageway 3 and outlet passageway5 and movably supported for axial displacement with respect to the body2 by a flexible sealing ring 10.

The clapper 9 forms, with an intermediate wall 11 of the body 2, a maincontrol chamber 12 which is completely isolated from the inletpassageway 3 except for a line 13 which communicates therebetween. Acheck valve 114 permits flow from the inlet passageway 3 through theline 13 and into the chamber 12 but prevents reverse flow.

' chamber 19.

elongated stem 24 which at the lower end 25 thereof is A suitablemanually operated valve 15 is provided to permit an auxiliary input ofwater to the line 13 for the original setting of the control valve inthe usual manner.

A flow-restricting orifice member 16 is inserted between the maincontrol chamber 12 and'the line 13 to permit full line pressure to beexperienced in the chamber 12 under static conditions but severelyrestrict the rate of inflow into the chamber 12 for creating a pressuredrop therein to operate the clapper 9 as described more fullyhereinafter.

The clapper 9 is normally maintained in closed position against anannular seal 17 carried on the body 2 adjacent the mouth or lip 18 ofthe inlet passageway 3.

The clapper 9 is maintained in said closed position by the pressure inthe chamber 12 caused by the bleeding in through the pipe 13 of thepressure in the inlet passageway 3 or, initially, through the manuallyoperated valve forms an auxiliary control chamber 19 located up aboveand adjacent the main control chamber 12. A control flow line 20 isconnected and communicates between the outlet passageway and theauxiliary control chamber 19. A piston mechanism 21 includes a head 22operatively communicating with the auxiliary control chamber 19 througha flexible diaphragm 23- which provides a seal to prevent fluid flowpast the head 22 from the control The piston mechanism 21 also has anseparable from but is adapted to selectively abut the center of theclapper 9. The stem 24 extends upwardly through suitable sealing members26 which are threadedly engaged with the body 2 at 27 and are adapted topermit the longitudinal sliding of the stem 24.

The piston mechanism 21 is responsive to a pressure increase in theauxiliary control chamber 19 to help urge the clapper 9 toward closedposition as illustrated in FIGS. 1 and 2. It is to be understood thatthe clapper 9 and piston head 22 only together and not separately have atotal pressure exposed area suflicient to close the clapper 9. Thisoccurs upon the introduction of inlet passageway pressure into the maincontrol chamber 12 through the line 13 and the introduction of pressureinto the auxiliary control chamber 19 caused by flow past the clapper 9into the outlet passageway 5, which pressure is transferred to thechamber 19 through the control flow line 20. It is to be furtherunderstood that the pressure in the inlet passageway 3 which isexperienced inthe main control chamber 12 is alone suiiicient tomaintain the clapper 9 in a closed position after closure thereof.

.Also, -a release of pressure in the main control chamber mannerdescribed hereinafter for drainingthe chamber 12 at a faster rate thanfluid can be replenished through the flow restricting member 16 forreducing the pressure in the chamber 12 to permit opening of the clapper9.

Referring particularly to FIG. 1 which depicts one example of an emptypipe fire extinguishing system, the extinguishing fluid pipe network 7has a plurality of spaced open sprinkler heads 31 connected in parallelrelationship and adapted to simultaneously discharge a spray of watertherefrom into the protected area of a building or the'like (not shown).The empty pipe system in the illustrated example has a pilot line 32connected to the release flow line 28 and extending into the protectedareas with the pipe network 7. The pilot line 32 has heat responsivenormally closed release valves thereon which may be of the fusing linktype as shown at 33 or the rate-of-rise type as shown at 34 or anycombination of the tWo and/or other types of heat responsivemechanically operated release valves desired or dictated by specificconditions. The heat responsive release valves 33 and 34 are adapted toselectively open when activatedby suitable environmental conditions tonormally cause a pres sure drop in the release flow line 28 for open-ingthe clapper 9 which results in a fluid flow into the network input 6 andout the open sprinkler heads 31 for extinguishing a fire.

Referring to FIG. 2 a plurality of parallel connected heat responsiverelease valves are connected in extinguishing fluid pipe network 8 andmay be of the fusing link spray head type as shown at '35 or therate-of-rise type as shown at 36 or any combination of the two and/orother types of heat responsive mechanically operated release valves. Incontrast to the empty pipe system illustrated in FIG. 1 the'pipe network8 of FIG. 2 contains liquid or air under pressure depending upon Whethera wet pipe or dry pipe system is desired.

When conditions are encountered which cause an opening of one or more ofthe valves 35 and 36 the air or liquid contained in the network 8 bleedstherefrom causing a pressure drop in the outlet passageway 5. Thispressure drop is experienced or detected in the pipe 20 and istransmitted to a pipe '37 communicating with the pipe 20. The pipe 37 inturn communicates with a suitable release device 38 which is responsiveto a small drop in pressure in the pipe 37 to initiate the opening of anormally closed pipe 39 for discharging into an open or drain pipe 40.

types, however, in the illustrated example it comprises a closed chamber41 supplied with air under constant pressure by a regulator 42 suppliedby a suitable air source 43. A suitable flexible diaphragm 44, forming aportion of the chamber 41, connects with a release arm 45. The diaphragm44 also forms a portion of a lower chamber 41' which communicates withthe pipe 37. In operation, if air or liquid in the chamber 41' islowered a predetermined amount, e.g., one p.s.i., a pressuredifierential is created between the chambers 41 and 41 which distendsthe diaphragm 44 sufiiciently to move the arm 45 to a release positionpermitting free flow or dumping from the tube 39 into the tube 40. Therelease device 38, when once tripped, requires a manual reset before theflow path between the pipes 39 and 40 is again blocked.

The pipe 39 in FIG. 2 communicates with the release flow line 28 at 46.An actuation of one or more of the valves 35 and 36 causes a pressuredrop in the outlet passageway 5 which results in flow from the pipe 39into the pipe 40 and thereby drops the pressure in the main controlchamber 12 for inducing main valve operation as noted above with respectto FIG. 1.

Referring now to the fire extinguishing systems shown in both FIGS. 1and 2, a pressure sensitive switch 47 communicates with the release flowline 28 for sensing a drop of pressure therein signifying the opening ofthe clapper 9. A normally open solenoid controlled valve 48 isoperatively connected in series in the release flow line 28 between therespective heat responsive release valves (33 and 34, or 35 and 36) andthe main control chamber 12. It is to be understood with respect to thefire extinguishing system of FIG. 2 that the release device 38 forms apart of the operative connection between the heat responsive vflves 35and 36 and the normally open solenoid controlled valve 48-. The valve 48during electrical actuation closes to block flow and thus preventdischarge therepast from the release flow line 28.

A first time delay relay 49 described more fully hereinafter iselectrically connected between the pressure switch 47 and the normallyopen solenoid controlled valve 48 and is of the type which isresponsive, upon the sensing of a pressure drop by the pressure switch47, to first delay for a pre-set time period and then cause theactuation (closing) of the valve 48.

Normally closed solenoid controlled valves 59/ and 51 are electricallyconnected in parallel and are operatively connected in parallel relationon the release flow line 28 between the normally open solenoidcontrolled valve 48 and the main control chamber 12. The use of twovalves 50 and 51, which provide duplication in function, rather than asingle solenoid controlled valve is merely for the purpose of betterinsuring a successful operation when the needed function is called for.The normally closed valves 50 and 51, during electrical actuation, opento permit flow from the release flow line 28 out open-ended or drainpipes 52 and 53 respectively. It is noted that the valves 50 and 51during actuation permit flow from the release flow line 28 upstreamfirom the valve 48 to counter the effect (pressure rise in flow line 28)of a closure of the valve 48 when conditions, described hereinafter, sorequire.

A plurality of series connected normally closed circuit thermostats 5'4are located in the areas serviced by the fluid distribution network andare adapted to selectively open at a predetermined above normalenvironmental temperature and close below said above normal temperature.A second time delay relay 55 is electrically connected in a mannerdescribed below between the normally closed solenoid vmves 5!) and 51and the thermostats 54. The time delay relay 55 is of the typeresponsive upon the interruption of current flow (sensing of said abovenormal temperature by one or more of the thermostats 54) to immediatelyactuate the normally closed solenoid valves 50 and 51 to open positionand maintain the actuation until the lapse of a pre-set time periodfollowing the re-establishment of current flow (closing of all thethermostats 54). The time delay relay 55 then interrupts current flow tothe valves 50 and 51 causing them to return to their normally closedposition whereby fluid can no longer be released from the pipe '28through the open ended or drain pipw 52 and 53.

Electrical energy for the above described electrical components isfurnished by the usual commercial or house power source indicated at 56,however, it is desirable that an auxiliary power supply schematicallyindicated at 57 be supplied in parallel with the house power source tooperate the system for an extended period in the event of house powerfailure which may occur during a fire or other unusual circumstances.

Referring to the schematic wiring diagram shown in FIG. 4 therelationship between the electrical components of this invention may bemore readily understood. The thermostat contacts 54' are closed below apredetermined temperature and are connected together in series with anormally closed push-button 58 and the time delay relay 55. Thepush-button 58 permits the testing of the time delay relay 55 withouthandling the thermostats which are normally at inaccessible locations.The time delay relay 55, when receiving current through the thermostatcontacts 54', maintains relay contacts 55 and 55 open which respectivelyinterrupt circuits through the solenoid coils 5t) and 51' of thesolenoid controlled valves 50 and 51, maintaining the latter in theirnormally closed condition during monitoring. The opening of one or moreof the thermostat contacts 54' causes the time delay relay 55 to closethe contacts 55' and 55" actuating the solenoid coils 5i) and 51' whichopens the valves 50' and 51 for dropping or maintaining the pressure inthe release flow line 28 below that necessary for closure of the clapper9. As noted above, a pre-set time delay elapses after completion of thecircuit through the thermostat contacts 54 before the contacts 55 and55" are closed.

Normally open contacts 47 are connected in series with the time delayrelay 49 and are closed when the pressure switch 47 detects a drop inpressure in the release flow line 28. The closure of the contacts 47'completes a circuit to the time delay relay 49' which, after the lapseof a pre-set time period, closes a normally open contact 49' whichcompletes a circuit through the solenoid coil 48' of the normally openvalve 48 for closing same. The current flow through the time delay relay49 also causes an immediate closure of the normally open time delayrelay contacts 49" which bypasses the pressure switch contacts 47 forlocking in the time delay relay 49. In order to reset the time delayrelay 49 after actuation by the pressure switch 47, a manual normallyclosed reset button 59 connected in series with the contacts 4-9 must beused.

The locking in of the time delay relay 49 results in the closing of therelease flow line 28 upstream from the heat responsive release valves 33or 34 (35 or 36) to permit an increase in pressure in the main controlchamber 12 when the valves 50 and 51 are closed even though the releasevalves 33 or 34 (35 or 36) remain open.

The operation of the invention is as follows: During normal monitoringall the heat responsive release valves 33 or 34 (35 or 36) are closed,the solenoid valves 50 and 51 are closed, the solenoid valve 48 is openand the contacts 47 of the pressure switch 47 are held open by thepressure in the release flow line 28 communicating with the pressure. inthe main control chamber 12 which holds the clapper 9 in closedposition. If a fire originates, the heat thereof causes an actuation ofone or several of the heat responsive release valves or an opening ofone or more of the thermostats. 54 or both. If the former occurs,pressure is released through the heat responsive release valves,resulting in a rapid flow through the release flow line 28 past therelease valves causing the clapper 9 to open and flood the fireextinguishing distribution system. If the latter occurs, fluid flowsfrom the release flow line 28 out the open or drain pipes 52 and 53 andthe same opening of the clapper 9 occurs- It is noted with regard to thewet or dry pipe system of FIG. 2 that no fire extinguishing fluid willbe sprayed until at least one of the heat responsive release valves 35or 36 actually opens, however, significant time may be saved in havingthe clapper 9 open and under line pressure prior to the actual call forliquid as signified by a release valve operation. When a drop inpressure in the release flow line 28 occurs, the pressure switch 47energizes the time delay relay 49 which, after a pre-set time periodduring which fire extinguishing fluid. is able to freely flow into theaffected area, causes the valve 48 to close and remain closed. If thesolenoid valves 50* and 51 have not been opened, or have been permittedto reclose after opening, flow through the release flow line 28 willthen be stopped and pressure will build up in the main control chamber12 which, when augmented by the pressure of the piston stem 24 againstthe clapper 9, will result in a closure of the main control valve 1.Should the fire not be out when the valve 48 closes, one or more of thethermostats 54 will remain open and only after a pre-set delay periodfor quenching flow following the closure of all the thermostats 54 willthe solenoid valves 50 and 51 close to permit the closure of the mainvalve 1. If the sprinkler system is shut oil? by closure of the valves48, 50 and 51 and a smoldering fire again ignites, one or more of thethermostats 54- will again open 7 resulting'in' an opening of the valves50 and 51 which causes the opening of the main valve 1. This cycle isrepeatable and automatically occurs as many times as is necessary forcompletely extinguishing the fire. If an electrical power failureoccurs, the normally open solenoid controlled valve 48 opens and remainsopen to prevent sprinkler system shut-oil except by conventional manualmeans (not shown).

It'is noted that the use of the above described control system willresult in rapid reliable actuation of the sprinklers and yetautomatically initiate shut-off and subsequent cycling to minimizedamage by either re-ignition or excess extinguishing fluid. It isfurther noted that the system is fail-safe and even in case of theremote possibility of a complete power failure before, during or after afire, the system reverts to the same operation common prior hereto.

Referring to FIG. 3, there is illustrated the main control valve 1 withthe clapper 9 in open position. Also in FIG. 3, there is illustrated theuse of a pressure regulating valve 61 with the main control valve 1 forthe purpose of controlling the pressure in the outlet passageway duringflow. In the embodiment of FIG. 3, the release flow line 28 willcommunicate with the valves 48, 50 and Slim the same manner asillustrated in FIGS. 1 and 2, however, instead of opening directly intothe main control chamber 12, the release flow line communicates with thepressure regulating valve 61. A release in pressure in the release flowline 28 in a manner described above causes a flow from the main controlchamber 12 through a pipe 62 communicating between the chamber 12 andvalve 61 and through a passageway 63 in the valve 61 and out throughthe'flow line 28. A line 64 communicates between the control fiow line20 and the valve 61, the fluid flow in the line 64 being separated fromthe passageway 63 by a flexible diaphragm 65. When the pressure in theoutlet passageway 5 reaches a predetermined amount, the diaphragm 65displaces a spring-urged plug 66 into a position for restricting theflow between the pipe 62 and release fiow line. 28 which results in anincrease of pressure in the main control chamber 12 reducing thequantity of fluid flowing through the outlet passageway 5 and therebyreducing pressure therein. An excessively reduced pressure in the outletpassageway 5 is sensed by the diaphragm 65 for again increasing fiow inthe line 28 which causes pressure to decrease in the main controlchamber 12. Thus the pressure in the outlet passageway 5 may beregulated when flow is called for and the regulation thereof receives nofunctional interference from the above described valves 48, 50 and 51located downstream on the release flow line 28.

It is to be understood that while certain forms of this invention havebeen illustrated and described, it is not to be limited to the specificforms or arrangement of parts herein described and shown except insofaras such limitations are included in the claims.

What I claim and desire to secure by Letters Patent is:

1. In a fire extinguishing system including a fluid actuated maincontrol valve having a body forming an inlet passageway connected to asource of fluid under pressure and an outlet passageway connected to asprinkler network and an operating portion, said main control valvebeing responsive in opening and closing operation to a respectivedecrease and increase of fluid pressure in said operating portionthereof;

(a) means for normally maintaining a pressure in said operating portionsufiicient to maintain said main control valve closed,

(b) a normally closed release flow line communicating with saidoperating portion and adapted to reduce the pressure in said operatingportion to open said main control valve in the event of flow throughsaid release flow line,

(c) single operation heat responsive release means as- 8 sociated withsaid release fiow' line for permitting flow through said release flowline,

(d) means communicating with said release flow line for sensing apressure drop signifying the opening of said main control valve,

(e) a normally open valve operatively connected in series in saidrelease fiow line between said heat re sponsive release means and saidoperating portion and adapted while closed to block flow past saidnormally open valve,

. (f) means operatively connecting said pressure sensing means and saidnormally open valve and responsive upon the sensing of a pressure dropby said pressure sensing means to delay for a pre-set time period andthen cause the closing of said normally open valve,

(g) a normally closed valve operatively connected in parallel to saidrelease flow line between said normally open valve and said operatingportion and being adapted while open to permit main control valveopening flow from said release flow line upstream from said normallyopen valve, and

(h) heat sensing means operatively connected to said normally closedvalve and adapted to open said normally closed valve above apredetermined temperature and close said normally closed valve belowsaid predetermined temperature,

(1') whereby after fire extinguishing flow caused by said heatresponsive release means said main control valve is automaticallyreclosed after a predetermined time period to limit fluid damage unlessthe temperature remains sufficiently high for actuating said heatsensing means, and said main control valve is automatically reopenedafter being reclosed in case of a reignition after the temperature hasbeen lowered.

2. The system of claim 1 wherein;

. (a) said means for normally maintaining a pressure in said operatingportion is a restricted line communicating with said inlet passageway.

3. The system of claim 1 wherein;

(a) said heat responsive release means are fusable link controlledvalves.

4. The system of claim 1 including;

. (a) means for delaying the closing of said normally closed valve aftersaid heat sensing means signals for closing thereof to permit additionalfire extinguishing flow.

5. In a fire extinguishing system including a fluid actuated maincontrol valve having a body forming an inlet passageway connected to asource of fluid under pressure and an outlet passageway connected to asprinkler network and an operating portion, said main control valvebeing responsive in opening and closing operation to a re spectivedecrease and increase of fluid pressure in said operating portionthereof;

(a) a restricted flow line connected between said main control valveinlet passageway and said operating portion for normally maintainingsaid main control valve closed,

(b) a normally closed release flow line communicating with saidoperating portion,

(0) a plurality of parallel connected single operation heat responsiverelease valves operatively associated with said release flow line andadapted to selectively open to permit a fluid flow in said release flowline sufficient to normally cause a pressure drop in said operatingportion for opening said main control valve,

(d) a source of electrical current,

(2) a pressure switch communicating with said release flow line and saidcurrent source and adapted to produce an electrical signal upon sensinga pressure drop signifying the opening of said main control valve,

(f) a normally open solenoid controlled valve operatively connected inseries in said release 'fiow line between said heat responsive releasevalves and said operating portion and being adapted only whileelectrically actuated to close and block flow downstream therefrom insaid release flow line,

(g) a first time delay relay electrically connected 'between saidpressure switch and said normally open solenoid controlled valve, saidfirst time delay relay being responsive upon the sensing of a pressuredrop sageway pressure into said main control chamber and theintroduction of pressure into said auxiliary control chamber caused byflow past said clapper into said outlet passageway, the inlet passagewaypressure in said main control chamber being alone sufiicient to maintainsaid clapper in a closed position after closure thereof,

by said pressure switch to delay for a pre-set time period and thencause the closing of said normally open solenoid controlled valve,

(h) at least one normally closed solenoid controlled valve operativelyconnected in parallel .to said release flow line between said normallyopen solenoid controlled valve and said operating portion and beingadapted only while electrically actuated to open and permit a fluid flowfrom said release i'low line up stream from said normally open solenoidcontrolled valve sutlicient to cause a pressure drop in said operatingportion for opening said main control valve,

-(1') at least one normally closed circuit thermostat connected withsaid current source and adapted to open at a predetermined above normaltemperature and close below said above normal temperature, and

(j) a second time delay relay electrically connected between saidnormally closed solenoid controlled valve and said thermostat, saidsecond time delay relay being responsive upon the sensing of said abovenormal temperature by said thermostat to immediately open said normallyclosed solenoid controlled valve and maintain same open for a pre-settime period following the closing of said thermostat and then permit thereclosing of said normally closed solenoid controlled valve,

(k) whereby after fire extinguishing flow said main control valve isautomatically reclosed after a pre- (c) a normally closed release flowline communicating with said main control chamber,

(d) a plurality of parallel connected single operation heat responsiverelease valves operatively associated with said release flow line andadapted to selectively open to normally cause a pressure drop in saidrelease fiow line in the event of fire for opening said clapper,

(e) a pressure switch communicating with said release flow line forsensing a drop of pressure signifying the opening of said clapper,

(f) a normally open solenoid controlled valve operatively connected inseries in said release flow line between said heat responsive releasevalves and said main control chamber and being adapted while closed toblock flow in said release flow line upstream from said normally opensolenoid controlled valve,

(g) a first time delay relay operatively connected between said pressureswitch and said normally open solenoid controlled valve, said first timedelay relay being responsive upon the sensing of a pressure drop by saidpressure switch to delay for a pre-set time period and then cause theclosing of said normally closed solenoid controlled valve,

(h) a normally closed solenoid controlled valve operatively connected inparallel to said release flow line between said normally open solenoidcontrolled valve and said main control chamber and being adapteddetermined time period to limit fluid damage unless the temperatureremains sufliciently high for opening said thermostat, and said maincontrol valve is autowhile open to permit flow from said release flowline upstream from said normally open solenoid controlled valve,

matically reopened after being reclosed in case of a reignition andremains open a predetermined period after the temperature has beenlowered sufiiciently for closing said thermostat.

6. The system of claim 5 including;

(a) a plurality of said thermostats, said plurality of thermostats beingseries connected.

7. The system of claim 5 wherein;

(a) said heat responsive release valves are control-led (i) a pluralityof series connected normally closed circuit thermostats adapted toselectively open at a predetermined above normal temperature and closebelow said above normal temperature, and

(j) a second time delay relay connected between said normally closedsolenoid controlled valve and said thermostats, said second time delayrelay being responsive upon the sensing of said above normal temperatureby one or more of said thermostats to imby fusable links. mediately opensaid normally closed solenoid con- 8. In a fire extinguishing systemincluding a fluid trolled valve and maintain said latter valve open foractuated main control valve \having a body forming an a pre-set timeperiod following the closing of all of inlet passageway connected to asource of fluid under pres sure and an outlet passageway connected to asprinkler network; (k) whereby after fire extinguishing flow said main(a) a flow controlling clapper operatively located becontrol valve isautomatically reclosed after a pretween said inlet and outletpassageways and forming determined time period to limit fluid damageunless with said body a main control chamber, a restricted thetemperature remains sufiiciently high for actufiOW connected betweenmain COlltI'Ol. valve afing one or more of said then'nostats, and aidmain inlet p g y and Said m m contfol 0hflmbe13fiid control valve isautomatically reopened in case of a clapper e normally mamtamed closedPosmon reignition and remains open a predetermined time the inletPressure in Sal-F1 m Con/F01 chamlier period after the temperature haslowered sufliciently said clapper being responsive in opening operationfor closing all of Said thermostats.

to the relief of pressure in said mam control cham- 9. In a firsextinguishing system including a fluid ber, (b) Said body forming anauxiliary control chamber actuated mam control valve having a bodyforming an mlet passageway connected to a source of fluid under locatedadjacent said main control chamber, a control flow line connectedbetween said outlet passage- Pressure and an outlet PaSageWayPnneted tosPrlnkler Way and said auxiliary control chamber a Piston network and anoperatmg port1on, sa d mam control mechanism having a head operativelycommunicating valve being responsive in opening operat1on to a decreasewith said auxiliary control chamber and a stem enof fluid Pressure inSaid Operating P gaging said clapper, said piston mechanism being meansfor normally maintaining a Pressure in Said responsive to a pressureincrease in said auxiliary Operating Portion Sulficient to a ain aidmain control chamber to urge said clapper toward said Control ValveClosed,

closed position, said clapper and piston head only to- (b) a normallyclosed release flow line communicating gether having a total pressureresponsive area to with said operating portion and adapted to reduceclose said clapper upon the introduction of inlet pas the pressure insaid operating portion to open said said thermostats and then cause theclosure of said normally closed solenoid controlled valve,

main control valve in the event of flow through said release flow line,

(0) single operation heat responsive release means associated with saidrelease flow line for permitting flow through said release flow line,

(d) means for sensing the opening of said main control valve,

(e) means for closing said main control valve,

(7) means operatively connecting said sensing means and said means forclosing said main control valve and responsive upon the sensing of theopening of said main control valve to delay for a pre-set time periodand then cause the closing of said main control valve,

(g) means for selectively overriding the closing of said main controlvalve, and

(h) heat sensing means operatively connected to said overriding meansand adapted to cause said overa 12 riding means to open said maincontrol valve above a predetermined temperature and close said maincontrol valve below said predetermined temperature, (1) whereby afterfire extinguishing flow caused by said heat responsive release meanssaid main control valve is automatically reclosed after a predeterminedtime period to limit fluid damage unless the temperature remainssufiiciently high for actuating said heat sensing means, and said maincontrol valve is automatically reopened after being reclosed in case ofa reignition after the temperature has been lowered.

References Cited in the file of this patent UNITED STATES PATENTS Q2,099,069 Lowe et al Nov. 16, 1937 2,168,244 Rouse Aug. 1, 19392,421,303 Van Houten May 27, 1947

1. IN A FIRE EXTINGUISHING SYSTEM INCLUDING A FLUID ACTUATED MAINCONTROL VALVE HAVING A BODY FORMING AN INLET PASSAGEWAY CONNECTED TO ASOURCE OF FLUID UNDER PRESSURE AND AN OUTLET PASSAGEWAY CONNECTED TO ASPRINKLER NETWORK AND AN OPERATING PORTION, SAID MAIN CONTROL VALVEBEING RESPONSIVE IN OPENING AND CLOSING OPERATION TO A RESPECTIVEDECREASE AND INCREASE OF FLUID PRESSURE IN SAID OPERATING PORTIONTHEREOF; (A) MEANS FOR NORMALLY MAINTAINING A PRESSURE IN SAID OPERATINGPORTION SUFFICIENT TO MAINTAIN SAID MAIN CONTROL VALVE CLOSED, (B) ANORMALLY CLOSED RELEASE FLOW LINE COMMUNICATING WITH SAID OPERATINGPORTION AND ADAPTED TO REDUCE THE PRESSURE IN SAID OPERATING PORTION TOOPEN SAID MAIN CONTROL VALVE IN THE EVENT OF FLOW THROUGH SAID RELEASEFLOW LINE, (C) SINGLE OPERATION HEAT RESPONSIVE RELEASE MEANS ASSOCIATEDWITH SAID RELEASE FLOW LINE FOR PERMITTING FLOW THROUGH SAID RELEASEFLOW LINE, (D) MEANS COMMUNICATING WITH SAID RELEASE FLOW LINE FORSENSING A PRESSURE DROP SIGNIFYING THE OPENING OF SAID MAIN CONTROLVALVE, (E) A NORMALLY OPEN VALVE OPERATIVELY CONNECTED IN SERIES IN SAIDRELEASE FLOW LINE BETWEEN SAID HEAT RESPONSIVE RELEASE MEANS AND SAIDOPERATING PORTION AND ADAPTED WHILE CLOSED TO BLOCK FLOW PAST SAIDNORMALLY OPEN VALVE, (F) MEANS OPERATIVELY CONNECTING SAID PRESSURESENSING MEANS AND SAID NORMALLY OPEN VALVE AND RESPONSIVE UPON THESENSING OF A PRESSURE DROP BY SAID PRESSURE SENSING MEANS TO DELAY FOR APRE-SET TIME PERIOD AND THEN CAUSE THE CLOSING OF SAID NORMALLY OPENVALVE, (G) A NORMALLY CLOSED VALVE OPERATIVELY CONNECTED IN PARALLEL TOSAID RELEASE FLOW LINE BETWEEN SAID NORMALLY OPEN VALVE AND SAIDOPERATING PORTION AND BEING ADAPTED WHILE OPEN TO PERMIT MAIN CONTROLVALVE OPENING FLOW FROM SAID RELEASE FLOW LINE UPSTREAM FROM SAIDNORMALLY OPEN VALVE, AND (H) HEAT SENSING MEANS OPERATIVELY CONNECTED TOSAID NORMALLY CLOSED VALVE AND ADAPTED TO OPEN SAID NORMALLY CLOSEDVALVE ABOVE A PREDETERMINED TEMPERATURE AND CLOSE SAID NORMALLY CLOSEDVALVE BELOW SAID PREDETERMINED TEMPERATURE, (I) WHEREBY AFTER FIREEXTINGUISHING FLOW CAUSED BY SAID HEAT RESPONSIVE RELEASE MEANS SAIDMAIN CONTROL VALVE IS AUTOMATICALLY RECLOSED AFTER A PREDETERMINED TIMEPERIOD TO LIMIT FLUID DAMAGE UNLESS THE TEMPERATURE REMAINS SUFFICIENTLYHIGH FOR ACTUATING SAID HEAT SENSING MEANS, AND SAID MAIN CONTROL VALVEIS AUTOMATICALLY REOPENED AFTER BEING RECLOSED IN CASE OF A REIGNITIONAFTER THE TEMPERATURE HAS BEEN LOWERED.